EP0337453A2 - Canal d'injection à valve pour une des deux buses en tandem - Google Patents

Canal d'injection à valve pour une des deux buses en tandem Download PDF

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Publication number
EP0337453A2
EP0337453A2 EP89106615A EP89106615A EP0337453A2 EP 0337453 A2 EP0337453 A2 EP 0337453A2 EP 89106615 A EP89106615 A EP 89106615A EP 89106615 A EP89106615 A EP 89106615A EP 0337453 A2 EP0337453 A2 EP 0337453A2
Authority
EP
European Patent Office
Prior art keywords
nozzle
rearward
rear end
central
melt
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP89106615A
Other languages
German (de)
English (en)
Other versions
EP0337453A3 (fr
Inventor
Jobst Ulrich Gellert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0337453A2 publication Critical patent/EP0337453A2/fr
Publication of EP0337453A3 publication Critical patent/EP0337453A3/fr
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/28—Closure devices therefor
    • B29C45/2806—Closure devices therefor consisting of needle valve systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/2737—Heating or cooling means therefor
    • B29C2045/274—Thermocouples or heat sensors

Definitions

  • This invention relates generally to injection molding and more particular to an injection molding system having heated nozzles mounted in tandem, the rearward one being fixed in place and the forward one reciprocating between open and closed positions to provide valve gating.
  • Heated nozzles are well known in the art, and valve gating is usually provided by a valve pin driven by actuating mechanism to reciprocate in a central bore in the nozzle.
  • valve gating is usually provided by a valve pin driven by actuating mechanism to reciprocate in a central bore in the nozzle.
  • actuating mechanism When molding certain materials it is desirable to provide additional heat to the gate area to facilitate closing of the gate. In the past, this has been done by providing a valve pin of which a portion is formed by a "heat pipe" as disclosed in the applicant's U.S. patent number 4,125,352 entitled “Thermal Valve Pin” which issued November 14, 1978.
  • Another solution to this problem is to improve the conductivity of the valve pin by filling it with copper, as described in the applicant's U.S. patent number 4,406,609 entitled “Valve Pin and Method of Manufacture” which issued September 27, 1983.
  • valve gated injection molding system having two heated nozzles mounted in tandem with the rearward nozzle fixed in position and the forward nozzle being axially reciprocal and having a heated nose portion.
  • the invention provides an injection molding valve gated system comprising a forward first elongated heated nozzle mounted in a well in a cavity plate for reciprocal motion in an axial direction, the first nozzle having a rear end, a nose portion leading to a tip at a forward end which is in axial alignment with a gate extending from the well to a cavity, and a melt bore extending therethrough, having a central portion and a diagonal portion, the central portion extending from an inlet at the rear end and the diagonal portion extending from the central portion to a sealed space surrounding the nose portion leading to the gate, the first nozzle having an integral heating element, a portion of which extends into the nose portion of the first nozzle, actuating means adjacent the first nozzle to drive the first nozzle axially from a retracted open position to a forward closed position wherein the tip of the nose portion is seated in the gate, and a rearward second elongated heated nozzle having a rear end, a forward end, and
  • a forward elongated heated nozzle 10 and a rearward elongated heated nozzle 12 are mounted axially in tandem with the forward nozzle 10 reciprocally mounted in a well 14 in a cavity plate 16 and the rearward nozzle 12 seated in a well 18 in a support plate 20.
  • the forward nozzle 10 reciprocally mounted in a well 14 in a cavity plate 16
  • the rearward nozzle 12 seated in a well 18 in a support plate 20.
  • there can be additional plates and/or the plates can have different shapes, but the mounting of the nozzles 10,12 remains the same.
  • this invention is also applicable to a multi-cavity system having a heated manifold to distribute melt to a number of sets of nozzles mounted in tandem.
  • the forward nozzle 10 is made with a rear end 22 and a nose portion 24 with a tapered outer surface 26 leading to a tip 28 at the forward end 30 as described in the applicant's Canadian patent application serial number 549,518 filed October 16, 1987 entitled "Injection Molding Nozzle Having Grounded Heating Element Brazed into Pointed Tip".
  • the forward nozzle 10 has an enlarged collar portion 32 with an outer surface 34 which fits inside the inner surface 36 of the well 14.
  • sealing grooves 38 are provided in the outer surface 34 of the collar portion 32 to prevent leakage of pressurized melt between it and the surrounding surface 36 of the well 14 as the forward nozzle reciprocates between the open position shown in Figure 1 and the closed position shown in Figure 2 in which the tip 28 of the nose portion 24 is seated in a gate 40 leading to the cavity 42.
  • these grooves 38 gradually fill with plastic which carborizes and prevents leakage past them.
  • the forward nozzle 10 is heated by an electric heating element 44 which is described in detail in the applicant's Canadian patent application serial number 563,981 filed April 13,1988 entitled "Injection Molding Nozzle Having Multiple Thickness Heating Element and Method of Manufacture".
  • the heating element 44 has a helical portion 46 and a multiple thickness longitudinal portion 48 which extends centrally in the nose portion 24 to an air-hard tool steel insert portion 50 which forms the tip 28.
  • the heating element 44 has a single resistance wire 52 which is grounded by being brazed in a nickel alloy.
  • the rear end 54 of the heating element 44 extends radially outward through the collar portion 32 of the nozzle and is connected to a threaded stud 56.
  • the larger diameter stud 56 is surrounded by ceramic insulation 58 inside a cylindrical sleeve 60 to form a cold terminal 62, as described in detail in the applicant's Canadian patent application serial number 549,520 filed October 16, 1987 entitled "Method of Manufacture of Injection Molding Nozzle Electrical Terminal.”
  • the cold terminal 62 receives a lead 63 from an external power supply from which current flowing through to the ground heats the nozzle 10 and particularly the tip 28 of the nose portion 24 to a predetermined temperature.
  • the rear end 22 of the forward nozzle 10 has a central hollow sleeve portion 64 which extends rearwardly to an open mouth 66.
  • the melt bore 68 which extends through the forward nozzle 10 has a central portion 70 which extends from the mouth 66 and a diagonal portion 72 which extends from the central portion 70 to a space 74 which surrounds the nose portion 24 leading to the gate 40 and is sealed against leakage by the sealing grooves 38.
  • the rearwardly extending sleeve portion 64 of the forward nozzle 10 projects into the central melt bore 76 of the rearward nozzle 12, and has similar circumferentially extending sealing grooves 78 seated in its outer surface 80 to prevent leakage.
  • the rearward nozzle 12 has an insulation flange 82 which seats on a circumferential shoulder 84 of the support plate 20 to securely and accurately locate the nozzle 12 in a fixed position with an insulative air space 86 between it and the surrounding support plate 20. In this position, the central bore 76 of the rearward nozzle which extends from an inlet 88 at the rear end 90 to the forward end 92 is in axial alignment with the central portion 70 of the melt bore 68 through the forward nozzle 10.
  • the rearwardly extending sleeve portion slides inside the central melt bore 76 of the rearward nozzle 12 without jamming. While the forward end 92 of the rearward nozzle 12 is adjacent the rear end 22 of the forward nozzle 10 in the open position shown in Figure 1, sufficient space is provided between them to allow for thermal expansion of the rearward nozzle 12.
  • the rearward nozzle 12 is held securely in this position by a steel backplate 94 which is fastened to the rear end 90 by bolts 96 and has a relatively thin flanged portion 98 which extends outwardly and rearwardly to bear against a retaining collar 100.
  • the retaining collar is, in turn, secured to the cavity plate 16 by bolts 102.
  • the backplate 94 has a central melt bore 104 extending therethrough in alignment with the central melt bore 76 through the rearward nozzle 12 to receive pressurized melt from the nozzle 106 of a molding machine.
  • the rearward nozzle 12 also has an integral electrical heating element 108 and can, for instance, be made by the methods described in the applicant's U.S. patent number 4,403,405 which issued September 13, 1983 entitled “Sprue Bushing Connector Assembly and Method” and the applicant's Canadian patent application serial number 532,677 filed March 20, 1987 entitled "Injection Molding Nozzle and Method”.
  • the heating element 108 has a helical portion 110 which extends around the central melt bore 76 and a rear portion which extends radially outward to a cold terminal 112 which receives electrical power from an external source.
  • a thermocouple 114 with an outwardly extending lead 116 is provided to monitor the temperature adjacent the forward end 92 of the rearward nozzle 12.
  • the forward nozzle 10 is driven from the retracted open position to the forward closed position by a pneumatically actuated ring piston 118 which is mounted in the cavity plate 16 around the rearward nozzle 12.
  • the piston 118 has a flanged portion 120 which extends inwardly to bear against the rear end 22 of the forward nozzle 10.
  • a controlled source of pressurized air is connected to an air duct 122 which extends to apply pneumatic pressure to the rear end 124 of the piston 118.
  • the piston 118 has piston rings 126,127 which provide a pneumatic seal as the piston reciprocates.
  • the inwardly flanged portion 120 has small holes 128 therethrough to equalize the air pressure on both sides when the piston reciprocates.
  • melt is introduced from the molding machine nozzle 106 to the inlet 88 to the central bore 76 in the fixed rearward nozzle 12 and it flows into the mouth 66 of the melt bore through the forward nozzle 10 to the space 74 around the nose portion 24.
  • the force of the melt back pressure against the forward nozzle 10 in the larger nozzle well 14 drives the forward nozzle to the retracted open position, and the melt flows through the gate 40 and fills the cavity 42.
  • the space 74 remains filled with melt, some of which solidifies adjacent the cavity plate 16 in the area cooled by cooling water flowing through cooling conduits 130.
EP89106615A 1988-04-13 1989-04-13 Canal d'injection à valve pour une des deux buses en tandem Ceased EP0337453A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA563980 1988-04-13
CA000563980A CA1261575A (fr) 1988-04-13 1988-04-13 Entree a obturateur pour moulage par injection a buses d'injection en tandem

Publications (2)

Publication Number Publication Date
EP0337453A2 true EP0337453A2 (fr) 1989-10-18
EP0337453A3 EP0337453A3 (fr) 1990-05-02

Family

ID=4137822

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89106615A Ceased EP0337453A3 (fr) 1988-04-13 1989-04-13 Canal d'injection à valve pour une des deux buses en tandem

Country Status (5)

Country Link
US (1) US4836766A (fr)
EP (1) EP0337453A3 (fr)
JP (1) JPH01304922A (fr)
CA (1) CA1261575A (fr)
DE (1) DE3912209A1 (fr)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2010855C (fr) * 1990-02-23 1999-07-27 Jobst Ulrich Gellert Systeme de moulage par injection avec ajutage a ressort de tension
US5037598A (en) * 1990-04-16 1991-08-06 Husky Injection Molding Systems, Ltd. Reciprocating heated nozzle
US5501594A (en) * 1994-02-16 1996-03-26 Eastman Kodak Company Apparatus for forming a thermoplastic body
DE19548687B4 (de) * 1995-12-23 2004-01-08 EWIKON Heißkanalsysteme GmbH & Co KG Beheizte Nadelverschlußdüse
US5855934A (en) * 1997-05-27 1999-01-05 Tradesco Mold Limited Valve pin actuator
DE29809855U1 (de) * 1998-06-03 1998-08-20 Guenther Heiskanaltechnik Gmbh Nadelverschlußdüse
CA2286953A1 (fr) 1999-10-18 2001-04-18 Helen Zhuang Systeme d'injection
DE10062436A1 (de) * 2000-12-15 2002-06-20 Buehler Druckguss Ag Uzwil Verschlussdüse
US7179081B2 (en) * 2003-04-07 2007-02-20 Mold-Masters Limited Front-mountable, edge-gating nozzle
CA2463402C (fr) * 2003-04-07 2013-01-15 Mold-Masters Limited Buse de canal chauffant avec scellement de matiere fondue
US7306454B2 (en) 2003-04-07 2007-12-11 Mold-Masters Limited Front-mountable injection molding nozzle
US7160100B2 (en) * 2004-01-06 2007-01-09 Mold-Masters Limited Injection molding apparatus having an elongated nozzle incorporating multiple nozzle bodies in tandem
CA2482254A1 (fr) * 2004-04-07 2005-10-07 Mold-Masters Limited Buse d'injection modulaire a isolant thermique
US7462030B2 (en) * 2004-04-07 2008-12-09 Mold-Masters (2007) Limited Nozzle having a nozzle body with heated and unheated nozzle body segments
US7614869B2 (en) 2007-05-08 2009-11-10 Mold-Masters (2007) Limited Manifold nozzle connection for an injection molding system
US7845936B2 (en) * 2009-01-21 2010-12-07 Mold-Masters (2007) Limited Sealing arrangement for an edge gated nozzle in an injection molding system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3677682A (en) * 1970-03-09 1972-07-18 Ladislao Wladyslaw Putkowski Hot runner system
US3843295A (en) * 1973-05-24 1974-10-22 Bischoff Chemical Corp Injection molding machine with adjustable nozzle length means
US4557685A (en) * 1984-07-13 1985-12-10 Gellert Jobst U Heated nozzle for injection molding apparatus

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758248A (en) * 1972-12-20 1973-09-11 H Drazick Injection plastic feeder
JPS51125160A (en) * 1974-06-27 1976-11-01 Saito Kouki Kk Automatically opening or closing valve gate for plastic injection molding
CA1086014A (fr) * 1977-04-29 1980-09-23 Jobst U. Gellert Buse chauffante a aiguille..
JPS6112089Y2 (fr) * 1980-06-25 1986-04-16
CA1179813A (fr) * 1981-07-15 1984-12-27 Jobst U. Gellert Raccord pour masselotte de moule, et methode connexe
CA1167222A (fr) * 1981-07-15 1984-05-15 Jobst U. Gellert Pointeau d'obturation, et methode de fabrication connexe

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3677682A (en) * 1970-03-09 1972-07-18 Ladislao Wladyslaw Putkowski Hot runner system
US3843295A (en) * 1973-05-24 1974-10-22 Bischoff Chemical Corp Injection molding machine with adjustable nozzle length means
US4557685A (en) * 1984-07-13 1985-12-10 Gellert Jobst U Heated nozzle for injection molding apparatus

Also Published As

Publication number Publication date
JPH01304922A (ja) 1989-12-08
US4836766A (en) 1989-06-06
DE3912209A1 (de) 1989-10-26
CA1261575A (fr) 1989-09-26
EP0337453A3 (fr) 1990-05-02

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